CN112731349B - Noise point identification method and system for laser radar - Google Patents
Noise point identification method and system for laser radar Download PDFInfo
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- CN112731349B CN112731349B CN202011531624.8A CN202011531624A CN112731349B CN 112731349 B CN112731349 B CN 112731349B CN 202011531624 A CN202011531624 A CN 202011531624A CN 112731349 B CN112731349 B CN 112731349B
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- 239000013307 optical fiber Substances 0.000 claims abstract description 68
- 230000010287 polarization Effects 0.000 claims abstract description 12
- 239000000919 ceramic Substances 0.000 claims description 44
- 238000001514 detection method Methods 0.000 abstract description 26
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
- G01S7/481—Constructional features, e.g. arrangements of optical elements
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A90/00—Technologies having an indirect contribution to adaptation to climate change
- Y02A90/10—Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation
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Abstract
According to the noise identification method and system for the laser radar, under normal weather, a processor starts a first laser, laser scanning is conducted through a first optical fiber cantilever, an output light beam rotates by 90 degrees under the action of a quarter wave plate, and the reflected light enters a laser receiver after being reflected by a polarizer and filtered by a polarizer. Therefore, the laser receiver only receives the light beam with the second polarization, the influence of other stray light can be filtered, and noise is avoided. In severe weather conditions such as rain, snow, fog, haze, etc., the reflected light energy is attenuated. When the energy of the light beam received by the laser receiver is smaller than the noise threshold, the current detection point can be judged to be the noise, the laser radar is possibly affected by weather, the processor can start the second laser to supplement light, the energy of the emergent light beam is increased, the energy of the reflected light beam is larger than the noise threshold, and the accuracy of the detection result is ensured.
Description
Technical Field
The application relates to the technical field of radars, in particular to a noise identification method and system for a laser radar.
Background
Lidar is a generic term for laser active detection sensor devices, and operates generally as follows. The transmitter of the laser radar emits a beam of laser, the laser beam returns to the laser receiver after encountering an object through diffuse reflection, and the radar module multiplies the speed of light according to the time interval between the transmitted signal and the received signal and divides the speed of light by 2, so that the distance between the transmitter and the object can be calculated.
In recent years, the development and application of the laser radar provide a new technical means for acquiring traffic data, and compared with the devices such as an infrared sensor, a millimeter wave radar and the like, the laser radar has the advantages of high resolution, strong anti-interference capability, rich acquisition information, capability of working all day and the like, and is more and more widely applied. And under severe weather conditions such as rain, snow, fog, haze and the like, the loss of the reflected light beam is too large to obtain a good detection effect, so that detection noise points are formed, and the detection result is influenced.
Disclosure of Invention
Aiming at the defects in the prior art, the application provides a noise identification method and a system which can be used for a laser radar, and the method and the system can be used for
In a first aspect, the present application discloses a noise identification system useful in lidar comprising:
the device comprises a processor, a first laser, a second laser, a driving circuit, a shell, a piezoelectric ceramic tube, a first optical fiber, a second optical fiber, a polarizer, a collimating lens component, a quarter wave plate, a polaroid and a laser receiver;
the processor is electrically connected with the first laser, the second laser, the driving circuit and the laser receiver;
the first laser and the second laser both output first polarized laser; the light beam of the first laser is coupled to the input end of the first optical fiber, the first optical fiber is fixed on the piezoelectric ceramic tube, the first optical fiber extends out of the piezoelectric ceramic tube to form a first optical fiber cantilever, the light beam of the second laser is coupled to the input end of the second optical fiber, the second optical fiber is fixed on the piezoelectric ceramic tube, and the second optical fiber extends out of the piezoelectric ceramic tube to form a second optical fiber cantilever; the first optical fiber cantilever and the second optical fiber cantilever are identical in size and model and are arranged in parallel;
the piezoelectric ceramic tube is fixed in the shell through a fixing piece;
the polarizer, the collimating lens component and the quarter wave plate are sequentially arranged on the light-emitting light paths of the first optical fiber cantilever and the second optical fiber cantilever; the polarizer is used for transmitting the first polarized laser and reflecting second polarized light perpendicular to the polarization direction of the first polarized laser, the polarizer is obliquely arranged with the first optical fiber cantilever, and the polarizer faces the laser receiver; the polarizer is arranged between the polarizer and the laser receiver, and is used for transmitting the second polarized light.
It can be appreciated that the present application discloses a noise identification system for a laser radar, where the first laser is the main laser, and in normal weather, the processor turns on the first laser, and performs laser scanning through the first optical fiber cantilever, and the output light beam rotates 90 degrees under the action of the quarter wave plate, and the reflected light is reflected by the polarizer, filtered by the polarizer, and enters the laser receiver. Therefore, the laser receiver only receives the light beam with the second polarization, the influence of other stray light can be filtered, and noise is avoided. In severe weather conditions such as rain, snow, fog, haze, etc., the reflected light energy is attenuated. When the energy of the light beam received by the laser receiver is smaller than the noise threshold, the current detection point can be judged to be the noise, the laser radar is possibly affected by weather, the processor can start the second laser to supplement light, the energy of the emergent light beam is increased, the energy of the reflected light beam is larger than the noise threshold, and the accuracy of the detection result is ensured.
As an alternative embodiment, the distance from the free end of the first optical fiber cantilever to the center of the free surface of the piezoelectric ceramic tube is equal to the distance from the free end of the second optical fiber cantilever to the center of the free surface of the piezoelectric ceramic tube.
It can be understood that the first optical fiber cantilever and the second optical fiber cantilever are symmetrically arranged relative to the piezoelectric ceramic tube, which is beneficial to the driving of the piezoelectric ceramic tube to the two optical fiber cantilevers and the design of the collimating lens component.
As an alternative embodiment, the area where the outgoing beam of the first optical fiber cantilever irradiates the collimating lens component and the area where the outgoing beam of the second optical fiber cantilever irradiates the collimating lens component have overlapping portions.
It can be understood that the light energy of the overlapping part overlaps two light beam energies, and the light beam emitted by the overlapping part has higher energy, so that the attenuation of the light beam energy by severe weather conditions such as rain, snow, fog, haze and the like can be resisted, the energy of the reflected light beam is greater than a noise threshold value, and the accuracy of a detection result is ensured.
As an alternative embodiment, the first laser and the second laser both emit laser beams of a target band; and a filter is arranged between the polaroid and the laser receiver, and is used for transmitting the light beams of the target wave band and reflecting the light beams of other wave bands.
It will be appreciated that in addition to the above-described polarization filtering, the light beam received by the laser receiver is also filtered by the filter's wavelength. That is, the laser receiver only receives the second polarized target band light beam, so that the influence of other stray light can be filtered, and the occurrence of noise points is further avoided.
As an alternative embodiment, the processor includes: the starting module is used for starting the first laser and sending a first control signal to the driving circuit so as to control the piezoelectric ceramic tube to scan at a first horizontal scanning speed and a first vertical scanning speed; the receiving module is used for receiving a light beam receiving signal of the laser receiver, wherein the light beam receiving signal comprises current received light beam energy; and the judging module is used for judging the current scanning point as the noise point under the condition that the beam energy is lower than the noise point threshold value.
In a second aspect, the present application discloses a method for identifying noise applicable to a laser radar, where the method is applied to any of the foregoing noise identification systems applicable to a laser radar, and includes:
the first laser is turned on, and a first control signal is sent to the driving circuit to control the piezoelectric ceramic tube to scan at a first horizontal scanning speed and a first vertical scanning speed;
receiving a beam receiving signal of the laser receiver, wherein the beam receiving signal comprises current received beam energy;
and under the condition that the beam energy is lower than a noise threshold value, judging the current scanning point as the noise point.
It will be appreciated that in generally normal weather, the processor turns on the first laser and performs a laser scan through the first fiber cantilever. In severe weather conditions such as rain, snow, fog, haze, etc., the reflected light energy is attenuated. When the energy of the light beam received by the laser receiver is smaller than the noise threshold, the current detection point can be judged to be the noise point, and the laser radar can be affected by weather.
As an alternative embodiment, the method further comprises: and turning on the second laser in case that the continuous noise exceeds a first threshold.
It will be appreciated that the continued occurrence of noise indicates that lidar has been difficult to operate properly in the current environment. Therefore, the processor can start the second laser to supplement light, and increase the energy of the emergent light beam, so that the energy of the reflected light beam is larger than the noise threshold value, and the accuracy of the detection result is ensured.
As an alternative embodiment, the method further comprises: transmitting a second control signal to the driving circuit to control the piezoelectric ceramic tube to scan at a second horizontal scanning speed and a second vertical scanning speed under the condition that the continuous noise point exceeds a first threshold value; the second horizontal scanning speed is less than the first horizontal scanning speed; the second vertical scanning speed is less than the first vertical scanning speed.
It will be appreciated that the continued occurrence of noise indicates that lidar has been difficult to operate properly in the current environment. Therefore, the processor can reduce the scanning speed of the piezoelectric ceramic tube through the driving circuit, so that the stay time of the light beam at each scanning point is prolonged, the energy of the reflected light beam is improved by utilizing time integration, the energy of the reflected light beam is enabled to be larger than a noise threshold value, and the accuracy of a detection result is ensured.
As an alternative embodiment, the receiving the beam receiving signal of the laser receiver includes periodically receiving the beam receiving signal of the laser receiver, where the period is less than a horizontal scanning period and/or a vertical scanning period of the piezoelectric ceramic tube.
It can be understood that the receiving period of the laser receiver is smaller than the scanning period, which means that the laser receiver can receive the reflected light beam at least once in one swing of the optical fiber cantilever, thereby ensuring the detection precision of the laser radar.
Finally, the application also discloses an intelligent driving vehicle, wherein any noise identification system which can be used for the laser radar is arranged on the intelligent driving vehicle.
The beneficial effects of this application are embodied in:
the application discloses can be used to noise point identification system of laser radar, wherein first laser instrument is the main laser instrument, and under the general normal weather, the processor starts first laser instrument, carries out laser scanning through first optic fibre cantilever, and the light beam of output is under the effect of quarter wave plate, and its reflection light produces 90 degrees rotations, and this reflection light gets into laser receiver after the polarizer reflection, filters the back through the polarizer. Therefore, the laser receiver only receives the light beam with the second polarization, the influence of other stray light can be filtered, and noise is avoided. In severe weather conditions such as rain, snow, fog, haze, etc., the reflected light energy is attenuated. When the energy of the light beam received by the laser receiver is smaller than the noise threshold, the current detection point can be judged to be the noise, the laser radar is possibly affected by weather, the processor can start the second laser to supplement light, the energy of the emergent light beam is increased, the energy of the reflected light beam is larger than the noise threshold, and the accuracy of the detection result is ensured.
Drawings
In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings that are used in the description of the embodiments or the prior art will be briefly described below. Like elements or portions are generally identified by like reference numerals throughout the several figures. In the drawings, elements or portions thereof are not necessarily drawn to scale.
Fig. 1 is a schematic diagram of an electrical connection relationship of a noise identification system that may be used in a laser radar according to an embodiment of the present application;
fig. 2 is a schematic structural diagram of a noise identification system that may be used in a laser radar according to an embodiment of the present application;
FIG. 3 is a schematic diagram of another noise identification system for lidar according to an embodiment of the present application;
FIG. 4 is a schematic diagram of a processor of the noise identification system shown in FIG. 2 or FIG. 3 that may be used in a lidar;
fig. 5 is a schematic diagram of a noise identification method that may be used in a lidar according to an embodiment of the present application;
FIG. 6 is a schematic diagram of another method for recognizing noise that may be used in the lidar according to the embodiment of the present application;
FIG. 7 is a schematic diagram of another method for recognizing noise that may be used in the lidar according to the embodiment of the present application;
fig. 8 is a schematic diagram of an intelligent vehicle equipped with a noise identification system that can be used for a laser radar according to an embodiment of the present application.
Detailed Description
Embodiments of the technical solutions of the present application will be described in detail below with reference to the accompanying drawings. The following examples are only for more clearly illustrating the technical solutions of the present application, and thus are only examples, and are not intended to limit the scope of protection of the present application.
It is noted that unless otherwise indicated, technical or scientific terms used herein should be given the ordinary meaning as understood by one of ordinary skill in the art to which this application belongs.
As shown in fig. 1 and fig. 2, fig. 2 is a schematic structural diagram of a noise identification system that may be used in a laser radar according to an embodiment of the present application. The invention discloses a noise point identification system for a laser radar, which is arranged on an intelligent vehicle. The system comprises: the laser device comprises a processor 10, a first laser 20, a second laser 30, a driving circuit 40, a housing 50, a piezoelectric ceramic tube 60, a first optical fiber 21, a second optical fiber 31, a polarizer 81, a collimating lens assembly 82, a quarter wave plate 83, a polarizer 84 and a laser receiver 70.
As shown in fig. 1, the processor 10 is electrically connected to a first laser 20, a second laser 30, a drive circuit 40, and a laser receiver 70.
Wherein the processor 10 may send light source control signals to the first laser 20 and the second laser 30, respectively, to control the switching of the lasers; in addition, the processor 10 may transmit a scan control signal to the driving circuit 40 to control the driving circuit 40 to transmit a horizontal scan signal and a vertical scan signal to the piezoelectric ceramic tube so that the piezoelectric ceramic tube is scanned in a predetermined "Z" type scan path or spiral scan path.
As shown in fig. 2, since the laser light is coherently polarized light, both the first laser 20 and the second laser 30 output first polarized laser light, for example, both the first laser 20 and the second laser 30 output S-linearly polarized light. The light beam of the first laser 20 is coupled to the input end of the first optical fiber 21, the first optical fiber 21 is fixed on the piezoelectric ceramic tube 60, the first optical fiber 21 extends out of the piezoelectric ceramic tube 60 to form a first optical fiber cantilever 22, the light beam of the second laser 30 is coupled to the input end of the second optical fiber 31, the second optical fiber 31 is fixed on the piezoelectric ceramic tube 60, and the second optical fiber 31 extends out of the piezoelectric ceramic tube 60 to form a second optical fiber swing arm 32; the first fiber cantilever 22 and the second fiber swing arm 32 are identical in size and model and are arranged in parallel. The piezoceramic tube 60 is fixed in the housing 50 by a fixing member 51.
In the embodiment of the present application, after the first laser 20 is turned on, the first polarized laser beam output by the first laser 20 is output through the first optical fiber 21. After the second laser 30 is turned on, the first polarized laser beam output by the second laser 30 is output through the second optical fiber 31. Simultaneously, the processor 10 controls the piezoelectric ceramic tube 60 to perform scanning motion according to a preset scanning track through the driving circuit 40, so as to drive the first optical fiber cantilever 22 and the second optical fiber cantilever 32 to scan and swing.
With continued reference to fig. 2, a polarizer 81, a collimating lens assembly 82, and a quarter wave plate 83 are sequentially disposed on the light-emitting paths of the first optical fiber cantilever 22 and the second optical fiber swing arm 32; the polarizer 81 is configured to transmit the first polarized laser light and reflect the second polarized light perpendicular to the polarization direction of the first polarized laser light, the polarizer 81 is disposed obliquely to the first optical fiber cantilever 22, and the polarizer 81 faces the laser receiver 70; a polarizer 84 is arranged between the polarizer 81 and the laser receiver 70, the polarizer 84 being arranged to transmit light of the second polarization.
In the embodiment of the present application, the light beams (indicated by the dashed arrows in the figure) emitted by the first optical fiber cantilever 22 and the second optical fiber cantilever 32 pass through the polarizer 81, are collimated by the collimating lens assembly 82, and pass through the quarter wave plate 83. The light beams emitted from the optical fiber cantilevers 22 and 32 are reflected by the object to be detected and then are directed again to the polarizer 81 through the quarter wave plate 83 (as indicated by the solid arrow in the figure), the reflected light beams become second polarized light beams perpendicular to the polarization direction of the first polarized laser light after passing through the quarter wave plate 83, are reflected by the polarizer 81, and enter the laser receiver 70 through the polarizer 84.
In this embodiment of the present application, the above-mentioned lidar is a scanning type lidar, that is, the ground is scanned by an optical fiber scanning system according to a predetermined scanning path, for example, according to a "Z" type or spiral type scanning path. The laser radar is further provided with a laser receiver 70, and the laser beam fed back by each point of the scanning path received during the scanning process can determine whether an obstacle exists around the vehicle according to the time of receiving the fed back laser beam.
It will be appreciated that the present application discloses a noise identification system for use in a lidar wherein the first laser 20 is the primary laser and the processor 10 turns on the first laser 20 for laser scanning through the first fiber cantilever 22 in normal weather conditions, and the output beam is rotated by 90 degrees by the quarter wave plate 83, and the reflected light is reflected by the polarizer 81, filtered by the polarizer 84, and enters the laser receiver 70. Therefore, the laser receiver 70 receives only the light beam of the second polarization, and can filter out the influence of other stray light, thereby avoiding occurrence of noise.
In severe weather conditions such as rain, snow, fog, haze, etc., the reflected light energy is attenuated. When the energy of the beam received by the laser receiver 70 is less than the noise threshold, the current detection point can be determined as the noise, the laser radar may be affected by weather, the processor 10 can start the second laser 30 to supplement light, and increase the energy of the outgoing beam, so that the energy of the reflected beam is greater than the noise threshold, and the accuracy of the detection result is ensured.
As an alternative embodiment, the distance from the free end of first fiber cantilever 22 to the center of the free surface of piezoceramic tube 60 is equal to the distance from the free end of second fiber cantilever 32 to the center of the free surface of piezoceramic tube 60.
It will be appreciated that the symmetrical arrangement of the first fiber suspension arm 22 and the second fiber suspension arm 32 with respect to the piezo ceramic tube 60 facilitates the driving of the two fiber suspension arms 22 and 32 by the piezo ceramic tube 60 and also facilitates the design of the collimator lens assembly 82.
As an alternative embodiment, there is an overlap between the area where the outgoing beam of the first fiber cantilever 22 impinges on the collimator lens assembly 82 and the area where the outgoing beam of the second fiber cantilever 22 impinges on the collimator lens assembly 82, as shown by the overlap area 100 in fig. 2.
It can be understood that the light energy of the overlapping part overlaps two light beam energies, and the light beam emitted by the overlapping part has higher energy, so that the attenuation of the light beam energy by severe weather conditions such as rain, snow, fog, haze and the like can be resisted, the energy of the reflected light beam is greater than a noise threshold value, and the accuracy of a detection result is ensured.
As shown in fig. 3, as an alternative embodiment, the first laser 10 and the second laser 10 each emit a laser beam of a target wavelength band; a filter 85 is arranged between the polarizer and the laser receiver, and the filter 85 is used for transmitting light beams of a target wave band and reflecting light beams of other wave bands.
It will be appreciated that in addition to the polarization filtering described above, the light beam received by the laser receiver 70 is also filtered by the wavelength of the filter 85. That is, the laser receiver only receives the second polarized target band light beam, so that the influence of other stray light can be filtered, and the occurrence of noise points is further avoided.
As shown in fig. 4, fig. 4 is a schematic diagram of a processor of the noise recognition system for a laser radar shown in fig. 2 or 3. The processor 10 includes: a starting module 11, a receiving module 12 and a judging module 13. Wherein,
the starting module 11 is used for turning on the first laser 20 and sending a first control signal to the driving circuit 40 to control the piezoelectric ceramic tube 60 to scan at a first horizontal scanning speed and a first vertical scanning speed;
a receiving module 12 for receiving a beam reception signal of the laser receiver 70, the beam reception signal comprising a current reception beam energy;
and the judging module 13 is used for judging the current scanning point as the noise point under the condition that the beam energy is lower than the noise point threshold value.
It should be noted that, the functions of each functional module of the processor 10 in the noise point identifying system for a laser radar described in the embodiments of the present application may be specifically implemented according to the methods in the method embodiments of fig. 5, fig. 6 and fig. 7, and the specific implementation process may refer to the relevant descriptions of the method embodiments of fig. 5, fig. 6 and fig. 7, which are not repeated herein.
Fig. 5 is a schematic diagram of a noise identification method for a laser radar according to an embodiment of the present application. The invention discloses a method for identifying noise points of a laser radar, which is applied to any noise point identification system of the laser radar in fig. 2 or 3, and comprises the following steps:
501. the first laser is turned on, and a first control signal is sent to the driving circuit to control the piezoelectric ceramic tube to scan at a first horizontal scanning speed and a first vertical scanning speed.
502. A beam receive signal of the laser receiver is received, the beam receive signal including a current received beam energy.
503. And under the condition that the beam energy is lower than the noise threshold value, judging the current scanning point as the noise point.
It will be appreciated that in generally normal weather, the processor turns on the first laser and performs a laser scan through the first fiber cantilever. In severe weather conditions such as rain, snow, fog, haze, etc., the reflected light energy is attenuated. When the energy of the light beam received by the laser receiver is smaller than the noise threshold, the current detection point can be judged to be the noise point, and the laser radar can be affected by weather.
As an alternative embodiment, receiving the beam receive signal of the laser receiver includes periodically receiving the beam receive signal of the laser receiver with a period that is less than the piezo ceramic tube horizontal scan period and/or the vertical scan period.
It can be understood that the receiving period of the laser receiver is smaller than the scanning period, which means that the laser receiver can receive the reflected light beam at least once in one swing of the optical fiber cantilever, thereby ensuring the detection precision of the laser radar.
Fig. 6 is a schematic diagram of another noise identification method for a laser radar according to the present invention. The method further comprises the following steps relative to the noise identification method for the laser radar shown in fig. 5:
604. the second laser is turned on in the event that successive noise exceeds a first threshold.
It will be appreciated that the continued occurrence of noise indicates that lidar has been difficult to operate properly in the current environment. Therefore, the processor can start the second laser to supplement light, and increase the energy of the emergent light beam, so that the energy of the reflected light beam is larger than the noise threshold value, and the accuracy of the detection result is ensured.
As an alternative embodiment, receiving the beam receive signal of the laser receiver includes periodically receiving the beam receive signal of the laser receiver with a period that is less than the piezo ceramic tube horizontal scan period and/or the vertical scan period.
It can be understood that the receiving period of the laser receiver is smaller than the scanning period, which means that the laser receiver can receive the reflected light beam at least once in one swing of the optical fiber cantilever, thereby ensuring the detection precision of the laser radar.
Fig. 7 is a schematic diagram of another noise identification method for a laser radar according to the present invention. The method further comprises the following steps relative to the noise identification method for the laser radar shown in fig. 5:
704. and under the condition that the continuous noise exceeds the first threshold value, sending a second control signal to the driving circuit to control the piezoelectric ceramic tube to scan at a second horizontal scanning speed and a second vertical scanning speed.
In the embodiment of the application, the second horizontal scanning speed is smaller than the first horizontal scanning speed; the second vertical scanning speed is less than the first vertical scanning speed.
It will be appreciated that the continued occurrence of noise indicates that lidar has been difficult to operate properly in the current environment. Therefore, the processor can reduce the scanning speed of the piezoelectric ceramic tube through the driving circuit, so that the stay time of the light beam at each scanning point is prolonged, the energy of the reflected light beam is improved by utilizing time integration, the energy of the reflected light beam is enabled to be larger than a noise threshold value, and the accuracy of a detection result is ensured.
As an alternative embodiment, receiving the beam receive signal of the laser receiver includes periodically receiving the beam receive signal of the laser receiver with a period that is less than the piezo ceramic tube horizontal scan period and/or the vertical scan period.
It can be understood that the receiving period of the laser receiver is smaller than the scanning period, which means that the laser receiver can receive the reflected light beam at least once in one swing of the optical fiber cantilever, thereby ensuring the detection precision of the laser radar.
As shown in fig. 8, the present application also discloses an intelligent driving vehicle, where any of the above noise recognition systems 300 that can be used for the laser radar are installed on the intelligent driving vehicle 200.
The beneficial effects of the invention are as follows:
the application discloses can be used to noise point identification system of laser radar, wherein first laser instrument is the main laser instrument, and under the general normal weather, the processor starts first laser instrument, carries out laser scanning through first optic fibre cantilever, and the light beam of output is under the effect of quarter wave plate, and its reflection light produces 90 degrees rotations, and this reflection light gets into laser receiver after the polarizer reflection, filters the back through the polarizer. Therefore, the laser receiver only receives the light beam with the second polarization, the influence of other stray light can be filtered, and noise is avoided. In severe weather conditions such as rain, snow, fog, haze, etc., the reflected light energy is attenuated. When the energy of the light beam received by the laser receiver is smaller than the noise threshold, the current detection point can be judged to be the noise, the laser radar is possibly affected by weather, the processor can start the second laser to supplement light, the energy of the emergent light beam is increased, the energy of the reflected light beam is larger than the noise threshold, and the accuracy of the detection result is ensured.
Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the embodiments, and are intended to be included within the scope of the claims and description.
Claims (10)
1. A noise identification system for use with a lidar, comprising:
the device comprises a processor, a first laser, a second laser, a driving circuit, a shell, a piezoelectric ceramic tube, a first optical fiber, a second optical fiber, a polarizer, a collimating lens component, a quarter wave plate, a polaroid and a laser receiver;
the processor is electrically connected with the first laser, the second laser, the driving circuit and the laser receiver;
the first laser and the second laser both output first polarized laser; the light beam of the first laser is coupled to the input end of the first optical fiber, the first optical fiber is fixed on the piezoelectric ceramic tube, the first optical fiber extends out of the piezoelectric ceramic tube to form a first optical fiber cantilever, the light beam of the second laser is coupled to the input end of the second optical fiber, the second optical fiber is fixed on the piezoelectric ceramic tube, and the second optical fiber extends out of the piezoelectric ceramic tube to form a second optical fiber cantilever; the first optical fiber cantilever and the second optical fiber cantilever are identical in size and model and are arranged in parallel;
the piezoelectric ceramic tube is fixed in the shell through a fixing piece;
the polarizer, the collimating lens component and the quarter wave plate are sequentially arranged on the light-emitting light paths of the first optical fiber cantilever and the second optical fiber cantilever; the polarizer is used for transmitting the first polarized laser and reflecting second polarized light perpendicular to the polarization direction of the first polarized laser, the polarizer is obliquely arranged with the first optical fiber cantilever, and the polarizer faces the laser receiver; the polarizer is arranged between the polarizer and the laser receiver, and is used for transmitting the second polarized light.
2. The noise identification system for a lidar of claim 1, wherein:
the distance from the free end of the first optical fiber cantilever to the center of the free surface of the piezoelectric ceramic tube is equal to the distance from the free end of the second optical fiber cantilever to the center of the free surface of the piezoelectric ceramic tube.
3. The noise identification system for a lidar of claim 2, wherein:
and an overlapping part exists between the area where the emergent light beam of the first optical fiber cantilever irradiates the collimating lens component and the area where the emergent light beam of the second optical fiber cantilever irradiates the collimating lens component.
4. A noise identification system for a lidar according to claim 3, wherein:
the first laser and the second laser emit laser beams of a target wave band;
and a filter is arranged between the polaroid and the laser receiver, and is used for transmitting the light beams of the target wave band and reflecting the light beams of other wave bands.
5. The system for identifying noise for a lidar of claim 1, wherein the processor comprises:
the starting module is used for starting the first laser and sending a first control signal to the driving circuit so as to control the piezoelectric ceramic tube to scan at a first horizontal scanning speed and a first vertical scanning speed;
the receiving module is used for receiving a light beam receiving signal of the laser receiver, wherein the light beam receiving signal comprises current received light beam energy;
and the judging module is used for judging the current scanning point as the noise point under the condition that the beam energy is lower than the noise point threshold value.
6. A noise identification method using the noise identification system usable with a laser radar according to any one of claims 1 to 5, the method comprising:
the first laser is turned on, and a first control signal is sent to the driving circuit to control the piezoelectric ceramic tube to scan at a first horizontal scanning speed and a first vertical scanning speed;
receiving a beam receiving signal of the laser receiver, wherein the beam receiving signal comprises current received beam energy;
and under the condition that the beam energy is lower than a noise threshold value, judging the current scanning point as the noise point.
7. The method for identifying noise for a lidar of claim 6, further comprising:
and turning on the second laser in case that the continuous noise exceeds a first threshold.
8. The method for identifying noise for a lidar of claim 6, further comprising:
transmitting a second control signal to the driving circuit to control the piezoelectric ceramic tube to scan at a second horizontal scanning speed and a second vertical scanning speed under the condition that the continuous noise point exceeds a first threshold value;
the second horizontal scanning speed is less than the first horizontal scanning speed; the second vertical scanning speed is less than the first vertical scanning speed.
9. A method for identifying noise for a lidar according to any of claims 6 to 8,
the receiving the beam receive signal of the laser receiver includes,
and periodically receiving a light beam receiving signal of the laser receiver, wherein the period is smaller than the horizontal scanning period and/or the vertical scanning period of the piezoelectric ceramic tube.
10. An intelligent driving vehicle, wherein the intelligent driving vehicle is provided with the noise identification system for laser radar according to any one of claims 1 to 5.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA2087073A1 (en) * | 1992-01-13 | 1993-07-14 | C. Clifton Andressen | Differential polarization ladar |
| CN110118960A (en) * | 2019-05-29 | 2019-08-13 | 深圳市镭神智能系统有限公司 | Laser radar |
| CN110244281A (en) * | 2019-07-19 | 2019-09-17 | 北京一径科技有限公司 | A kind of laser radar system |
| CN110703275A (en) * | 2019-09-30 | 2020-01-17 | 深圳市速腾聚创科技有限公司 | Laser radar system and object identification method |
| CN111337900A (en) * | 2020-03-27 | 2020-06-26 | 广东博智林机器人有限公司 | Laser radar ranging system and laser radar |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10254762B2 (en) * | 2017-03-29 | 2019-04-09 | Luminar Technologies, Inc. | Compensating for the vibration of the vehicle |
| US10241198B2 (en) * | 2017-03-30 | 2019-03-26 | Luminar Technologies, Inc. | Lidar receiver calibration |
| CN108132472A (en) * | 2017-12-08 | 2018-06-08 | 上海禾赛光电科技有限公司 | Laser radar system |
-
2020
- 2020-12-23 CN CN202011531624.8A patent/CN112731349B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA2087073A1 (en) * | 1992-01-13 | 1993-07-14 | C. Clifton Andressen | Differential polarization ladar |
| CN110118960A (en) * | 2019-05-29 | 2019-08-13 | 深圳市镭神智能系统有限公司 | Laser radar |
| CN110244281A (en) * | 2019-07-19 | 2019-09-17 | 北京一径科技有限公司 | A kind of laser radar system |
| CN110703275A (en) * | 2019-09-30 | 2020-01-17 | 深圳市速腾聚创科技有限公司 | Laser radar system and object identification method |
| CN111337900A (en) * | 2020-03-27 | 2020-06-26 | 广东博智林机器人有限公司 | Laser radar ranging system and laser radar |
Non-Patent Citations (3)
| Title |
|---|
| 大气偏振模式图分布及仿生偏振导航技术;褚金奎;关乐;李世奇;张然;金仁成;崔岩;王立鼎;;遥感学报(第06期);全文 * |
| 大气压力探测用激光雷达的对称性分析;洪光烈;王钦;孔伟;吴金才;;红外(第02期);全文 * |
| 激光点云运动人体目标识别及运动信息提取;杜璞;张小艳;;激光杂志(第01期);全文 * |
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